Viscometric Determination of the Conformations and Sizes of Polyethylene Glycol Macromolecules in Aqueous Solutions

The kinematic viscosities of solutions of polyethylene glycol (PEG) of different molecular weights (1000, 1500, 3000, 4000, and 6000) are studied at 293.15–323.15 K in the 0–5 g/dL range of concentrations. Parameters are calculated according to the obtained data: characteristic viscosity, the Huggins constant, parameter α in the Kuhn–Mark–Houwink equation, characteristic viscosity in a θ solvent, the coefficient of swelling of the macromolecular coil in solution, root-mean-square distance of PEG macromolecular chain, and the length of Kuhn segments. It is found that the macromolecular coil is partially permeable for the surrounding liquid (water) and opens slightly. It was shown that the PEG molecules shrink as the temperature is raised, as is typical of flexible chain polymers.